Gas-liquid contact method



Oct. 24, 1961 F. YERZLEY 3,005,679

GAS-LIQUID CONTACT METHOD Original Filed March 22, 1956 4 Sheets-Sheet 1INVENTOR. fi /Av L yerz/ey BY am A TTORA/Ey Oct. 24, 1961 F. L. YERZLEY3,005,679

GAS-LIQUID CONTACT METHOD Original Filed March 22, 1956 4 Sheets-Sheet55 INV EN TOR.

y Fe/fx A. Yerz/ey Oct. 24, 1961 F. YERZLEY GAS-LIQUID CONTACT METHODOriginal Filed March 22, 1956 4 Sheets-Sheet 4 22x0 OP INV EN TOR.

ATTORNEY This invention relates to a gas-liquid contact method andapparatus, shown as a chemical hood or the like, i.e., apparatus whichprovides a work space for oper- 3,005,679 Patented Oct. 24,

2 I 22 (FIGS. '2" and 3') which will be referred to later. Resting uponthe horizontal frame composed of portions 14, 15, 16 and 17 is a member24 made of rectangular, seamless tubing and which is U-shaped in ahorizontal plane so that it registers with frame members 15, 16 and 17.The member 24 is also of welded-steel construction;

ations which may result in dust or dangerous fumes and V which providesfor disposal of such lay-products.-

Among the objects of the present invention are to provide aself-contained, unitary hood unit which purges the air from the hood offumes and dust before exhausting the air; to provide a hood unit whichmay be used with no exhaust from the room other than the regular airconditioning exhaust from the room; to provide a unitary hood unit whichmay be prebuilt in complete form and which requires only electrical,water Supply and drain connections thereto upon being installed; toprovide a hood unit which is portable in the sense that it can bereadily moved into the work-room and put into use and then be readilytransferred from location to location as occasion may require; toprovide a small, compact hood unit having the foregoing features andadvantages; and generally to improve the effectiveness, efiiciency andsimplicity of chemical-hood units.

Further objects, and objects relating to details and economies ofconstruction, operation and use, will more definitely appear from thedetailed description to follow. My invention is clearly defined in theclaims. In the claims, as well as in the description, parts of theconstruction and parts of the operating system may at times beidentified by specific names for clarity and convenience, but suchnomenclature is to be understood as having the broadest meaningconsistent with the context and with the concept of my invention asdistinguished from the pertinent prior art. The best form in which Ihave contemplated applying my invention is illustrated in theaccompanying drawings forming part of this specification, in which:

FIG. 1 is a somewhat diagrammatic exploded view'of a chemical-hood unitembodying the invention, the view being simplified and certain partsbeing omitted.

FIG. 2 is a partly diagrammatic front elevation of the chemical-hoodunit.

FIG. 3 is a transverse, vertical section of the chemicalhood unit takenin general on the line 3-3 of FIG. 2.

FIG. 4 is a longitudinal, vertical sectional view illustrating thescrubbing unit shown in FIGS. 1, 2 and 3, the plane of the section beinggenerally on the line 4-4 of FIG. 3.

Referring to FIG. 1, the complete chemical-hood unit includes threesubunits, viz., a base unit 10, a scrubbing unit 11 and an enclosureunit 12. When assembled as shown in FIGS. 2 and 3, the scrubbing unit 11nests within a sink in the base unit 10 and the enclosure unit 12overlies the two.

The construction of the base unit 10 will be understood from FIGS. 1, 2and 3. This unit comprises a horiz'ontal, rectangular frame preferablymade of rectangular, seamless tubing, the frame having front and backportions 14 and 15 and side portions 16 and 17. This frame is supportedby four legs 19. Attached to and supported by the horizontal frame is asink unit comprising a work surface or drainboard 20 which slopes towardand merges with a sink proper 21. The horizontal frame, the supportinglegs, the work surface and the sink may be of welded-steel construction.Supported from the rear legs 19, is a motor and blower unit designatedas a whole by The interior of the sink proper 21, the work surface 20,the top and front of frame member 14 and the in ward'ly-facing portionsof frame members 14, 15, 16 and 17 which lie above the sink unit arecovered with a inch-thick sheet of acid-resisting plastic, with sealedjoints. This may be the polyvinyl chloride sold by B. F. Good rich underthe name of Koros'eal. A fragment of covering is shown at 25 in FIG. 1.This covering is con: tinued upwardly over the tops of the threebranches'of member 24 and, when the enclosure member 12 is put in place,acts as a gasket between the member 24 and the enclosure unit 12. I Oncethe three subunits 10, 11 and 12 of the hood unit have been placed inassembled relation, this relationship may be retained in any suitablemanner, as by suitably located bolts or clamps (not shown). V

The scrubbing unit 11 which, as shown in FIG. 1, is generally boxlike asregards its exterior shape, rests in the sink 21 and is supported fromthe bottom of the sink by blocks or other suitable means which arespaced from one another, and may be perforated in addition, to permitliquid to flow freely in all directions beneath the scrubbing unit. Oneof'these blocks is shown at 26 in FIG. 3. The interior construction ofthe scrubbing unit will be described later.

The enclosure unit 12 has top 27, sides 29, 29, back 30 and atransparent front panel 31. The front edges of sides 29, 29 may beprovided with trim pieces 28, 28 which extend toward each other andoverlie the free ends of U-shaped member 24. Access to the work space 20is obtained through the rectangular space at 32 which extends across thefront of the enclosure unit. 12 and upwardly from the top of framemember 14 to the bot: tom edge of transparent panel 34 which lies in aninclined position and has its upper edge hinged to panel 31. A greaterdegree of accesstto the work space 20, and to the interior of theenclosure unit 12, may be ob; tained by swinging upwardly the hingedpanel 34. Fixed panel 31 and hinged panel 34 may each be made of thick,rigid sheets of suitable transparentplastic.

Reference will now be had to the showing in FIG. 4 of the scrubbing unit11 located in the sink 21. As will presently appear, the air and fumeswithin the enclosure unit 12 laden with fumes or dust generated in thevicinity of the work surface 20, are drawn downwardly around the outsideof the scrubbing unit 11, in at the bottom of the scrubbing unit, andupwardly through the scrubbing unit to remove the fumes and dust, afterwhich the cleansed air is drawn downwardly through a conduit andretgrned to the roomat a point below the level of the S111 There isprovided a water-discharge pipe 35 which leads through a trap 23 to adrain. The top or inlet of dis.- charge pipe 35 may be positioned abovethe bottom of the sink, as shown. Thus, when the apparatus is inoperation a depth of water will be maintained in the sink equal to theheight of discharge pipe 35 above the bottom of the sink. This waterlevel is indicated at 21a. The gas enters the scrubbing unit at orslightly below this water level. a

The scrubbing unit 11 is supported in the sink in the position shown inFIG. 4, resting on spaced blocks such as block 26 in FIG. 3 aspreviously referred to. The casing of the scrubbing unit 11 includes afront wall 36, a back wa1l37, a left-end wall 39, a right-end wall 40, atop 41 and a bottom 42. The bottom 42 projects horizontally a shortdistance beyond the vertical walls 36, 37, 39 and 40 and is provided, asshown in FIG. 4, with a short, upwardly extending lip 44 which extendsentirely around the perimeter of the bottom. Above discharge pipe 35 thebottom 42 is provided with a domelike member 45 which overlies thedischarge pipe 35 and provides a vent in conjunction with space forwater to flow from the sinkinto the top of pipe 35.

Referring to FIGS. 1 and 3, it will be seen that the bottom edge offront wall 36 is recessed upwardly for a considerable portion of itslength, providing an elongated slitlike port 36a. A similar elongatedslitlike port 37a is provided at the bottom of back wall 37 as shown inFIG. .4.- Air and fumes are drawn from the interior of enclosure unit 12through these two ports to the interior of the scrubbing unit 11. Afterentering the scrubbing unit 11, the air passes upwardly throughahorizontal wire screen 46, a layer of aggregate 47, another horizontalwire screen 49, the space between screen 49 and a third horizontalscreen 50, through a layer of aggregate 51 and thence through a fourthhorizontalrwire screen 52; The layers of aggregate 47 and 51 are keptsubstantially flooded with water issuing in finely divided form througha number of spray nozzles at 53 fed by pipes 54, and 55 see also FIG.3). Screen 46 supports the aggregate 47, screen 49 serving to retain theaggregate in fixed or unyielding position. Likewise screen 50 serves tosupport the aggregate layer 51, screen 52 overlying the aggregate layerto assure that the aggregate remains in a fixed position. 7

During its passage upwardly through the scrubbing chamber, the air isscrubbed and the dust and fumes removed therefrom. Upon reaching thespace above screen 52, the air is drawn over the top of verticalpartition 56, beneath the bottom of baffle 57 and into downwardly ex:tending exhaust conduit 59, in the path indicated by the filled withmarble chips as shown at 63 so that the water has to work its way slowlythrough the interstices between the chips before it reaches thedischarge pipe 35. These chips may be the same as in beds 47 and 51. Bythe time the water reaches the discharge pipe 35, it has been largelyneutralized by the action of the marble chips at 63.

Due to the negative pressure in exhaust conduit 59,

water will rise from the sink into the vertical chamber betweenpartition 56 and end wall 40 to the level indi-- cated at 210 since thischamber or conduit communicates with the space above aggregate bed 51and conduit 59. Horizontal baffies 65, 66 and 67 separate the water inthis chamber into more or less stratified layers.

' a muslin bag 72. The purpose of the muslin bag is to help diffuse theair, prevent drafts, and minimize blasts when the blower is started. Thelower curved bend between conduit sections 59a and 59b is sufiicientlybelow the upper recurved bend between conduit sections 5913 and 590 toprevent water from accidentally entering the serpentine arrow 60 Thisserpentine path involves abrupt result that the cleansed air isrelatively free of entrained ivaterfwhen it enters the air-dischargeconduit 59 that is under suction. p p i The aggregate in layers 47 and51 is composed of relatively small particles, that are. packed or shakentogether suificiently to prevent the individual particles from shiftingunder the action of air currents as the air is drawn upwardly throughthe layers of aggregate. Thus, the air being scrubbed cannot channel itsway through the aggregate, but instead is forced to widely disperse and,in finely divided form, come into contact with a very large area ofwater that is on the surface of the pieces of the aggregate and whichalso substantially fills the space between the pieces of the aggregatesince the supply of water is sufficient to maintain the beds ofaggregate at 47 and 51 in substantially flooded condition.

For the absorption of acid fumes, of nitric, hydroflublower. Ordinarilythere will be no water in this air conduit, but should water be drawnover into it for any reason the head of water between the two recurvedbends in the conduit is suflicient, because of the limited suction ofthe blower, to prevent water from being drawn into the blower. Any wateraccidentally collecting in the duct 59 can be removed through the drainplug 58, as shown.

The chemical-hood unit is provided with an electrical system, a watersystem and a drain connection which, upon installation of the unit, aresimply connected to points in the supply and drainage systems of thebuilding. Trap 23 (FIGS. 2 and 4) is shown as connected to the buildingdrain.

This application is a continuation of my prior application, Serial No.573,166, filed March 22, 1956, now abandoned.- I

' I claim:

a ,1. The method of contacting liquid and gas, comprising maintaining abed of particles of aggregate in a fixed position with the spacesbetween saidparticles constituting passages for liquids and gastherethrough, introducflow by gravity through the passages therein,counter-curoric, hydrochloric and others, I have employed an aggresomeconditions. I have used a scrubbing-chamber area,

in horizontal cross section of from one to four square feet per 100cubic feet of airper minute with depths of the aggregate (in both bedstaken together) up to eight inches, and with water fed by the sprays offrom one-half to two gallons per minute. J V l After descending throughthe beds of aggregate 51 and 47, the water passes through an outletopening 61 in the bottom 42 of the scrubbing unit. As shown in FIG. 4,this opening is remote from the water discharge pipe 35 and hence thewater must make its way quite a distance before entering the dischargepipe- The space in the sink beneath the bottom 42 of the scrubbing unitmay be rent to the induced up-fiow of said gas through said passages,and maintaining the fiow of said gas and of said liquid at a ratesufiicient to flood said bed to maintain the spaces between theparticles substantially filled with liquid during normal operation.

2. The method recited in claim 1, the passages through said aggregatebed being irregular, tortuous and interconnected throughout the bed.

3. The method recited in claim 1, the upward gas flow through the,passages in said bed being induced by suction from above said bed.

4. The method of contacting liquid and gas in countercurrent flow,comprising, downwardly flowing a liquid throughthe passages between theparticles in a fixed bed of particles of aggregate, forcibly passing gaswidely dis.

persed and in finely divided form through said passages upwardly throughthe liquid in said passages, and main? taining the flow of said gas andsaid liquid at a rate sufficient to flood said bed to maintain saidpassages substantially filled with liquid during normal operation.

5. The method of contacting liquid and gas, compris ing maintainingvertically spaced beds of particles'of aggregate with the particles infixed positions in said beds and with the spaces between said particlesconstituting tortuous and interconnected passages for said liquid andgas, introducing gas into a space beneath the lower of said beds andinducing a flow thereof upwardly through said beds and through the spacebetween said beds, introducing liquid onto the upper surface of theupper bed for down-flow by gravity progressively through said beds andthe space between them, counter-current to the induced up-fiow of gasthrough said beds, and maintaining the flow of said gas and of saidliquid at a rate sufiicient to flood said beds to maintain the spacesbetween the particles substantially filled with liquid during normaloperation.

6. The method recited in claim 5, said beds being positioned onedirectly above the other and of substantially the same horizontaldimensions.

7. The method of removing a constituent from a gas, comprising inducinga flow of said gas upwardly through a plurality of spaced, alined, fixedbeds of aggregate particles introducing a liquid onto the upper portionof an overlying aggregate bed for down flow by gravity through saidoverlying bed, then through the space between said beds, then through anunderlying bed in continuous flow, inducing a flow of gas, containingsubstances to be removed, upwardly through an underlying bed of saidaggregate particles, with the gas in widely dispersed, finely dividedform, while contacting said particles and the downflowing liquidflooding said bed, intermingling the particles of gas in the spacebetween said beds and continuing the induced flow thereof upwardlythrough an upper said bed of aggregate particles in the same widelydispersed, finely divided form, the flow of said gas and said liquidbeing maintained at a rate sufiicient to flood said beds and maintainingsaid passages substantially filled with liquid during normal operation,removing the cleaned gas from above said upper bed and discharging. theliquid with its removed substances from beneath said underlying bed.

References Cited in the file of this patent UNITED STATES PATENTS822,373 Knietsch June 5, 1906 940,595 Herreshofi Nov. 16, 1909 1,884,304Sheldon Oct. 25, 1932 1,962,525 Richardson June 12, 1934 2,043,109 McKeeJune 2, 1936 2,431,455 Blanding Nov. 25, 1947 2,715,359 Maclntosh Aug.16, 1955 2,878,099 Breuing et a1. Mar. 17, 1959

1. THE METHOD OF CONTACTING LIQUID AND GAS, COMPRISING MAINTAINING A BEDOF PARTICLES OF AGGREGATE IN A FIXED POSITION WITH THE SPACES BETWEENSAID PARTICLES CONSTITUTING PASSAGES FOR LIQUIDS AND GAS THERETHROUGH,INTRODUCING GAS BENEATH SAID AGGREGATE BED AND INDUCING A STEADY FLOWTHEREOF UPWARDLY THROUGH SAID BED, INTRODUCING LIQUID ONTO THE UPPERSURFACE OF SAID BED OF AGGREGATE FOR DOWNFLOW BY GRAVITY THROUGH THEPASSAGES THEREIN, COUNTER-CURRENT TO THE INDUCED UP-FLOW OF SAID GAS ANDOF SAID PASSAGES, AND MAINTAINING THE FLOW OF SAID GAS AND OF SAIDLIQUID AT A RATE SUFFICIENT TO FLOOD SAID BED TO MAINTAIN THE